The History Of The Earth -

4. The Rise of Mammals and Humans (66 Million Years Ago – Present)

The story of Earth is a 4.5-billion-year epic that began in a chaotic cloud of stardust and evolved into the vibrant, living world we know today. 1. The Fiery Beginning (4.5 Billion Years Ago) The History of the Earth

As the planet cooled, a solid crust formed. Steam from volcanic eruptions and ice-carrying comets condensed into the first . In these chemical-rich waters, the miracle happened: the first microscopic life appeared. Eventually, organisms called cyanobacteria evolved photosynthesis, pumping oxygen into the atmosphere for the first time—an event known as the Great Oxidation Event . 3. The Age of Complexity (541 – 66 Million Years Ago) organisms called cyanobacteria evolved photosynthesis